1. Field of the Invention
This invention relates to improvements in an airbag sensor for actuating an airbag restraint system to protect a vehicle passenger from coming into direct contact with either a steering wheel or a front windshield in the event of a serious vehicle collision, and more particularly to a locking releasing device for releasing the airbag sensor from locking for disabling the function of the airbag sensor.
2. Description of the Prior Art
A variety of airbag restraint systems have been proposed and put into practical use for an automotive vehicle. Such airbag restraint systems are usually arranged such that when an impact force at a vehicle collision exceeds a predetermined level, an airbag stored in its folded state in a padded steering wheel or an instrument panel is inflated and developed thereby softening an impact of a vehicle passenger against the instrument panel or the front windshield. The inflation of the airbag is accomplished by operation of an inflator. The inflator is operated upon actuation of an initiator carried out in response to a signal output from the sensor mechanism of an airbag sensor such as a collision sensor provided in the airbag restraint system. Thus, the airbag sensor sensor mechanism is adapted to sense the high impact force and trigger the inflation of the airbag.
The airbag sensor is equipped with a locking mechanism which is arranged to lock the sensor mechanism so as to prevent the airbag from unnecessarily inflating and developing during a maintenance or a test run of the vehicle. The locking mechanism is manually operated by a mechanic to lock the sensor mechanism during the maintenace or the like and to release the sensor mechanism from locking after completion of the maintenance or the like. It is thus, necessary that the locking mechanism have provisions to release the sensor mechanism from the locking when a user drives the vehicle equipped with the airbag restraint system.
However, an operation of releasing the locking mechanism from locking against the sensor mechanism has been accomplished by manually rotating a locking releasing bolt associated with the locking mechanism. This is carried out during a maintenance operation of the vehicle by a mechanic. Accordingly, there is the possibility that the vehicle equipped with the airbag restraint system may be supplied to a user in a state the locking mechanism has not yet been released from the locking. Thus, the conventional airbag sensor is unavoidably poor in operational reliability.